Micromorphological Changes in Planorbis (Müller, 1774) Tissues in Experimental Infection With Miracidia Cotylurus Sp. (Szidat, 1928)

During their life cycle at larval development stages, trematodes use various molluscs as their first intermediate host, migrate and reproduce asexually in them causing various responses in the form of degenerative changes and inflammatory processes. The purpose of our research was to study histological pattern of tissues in the first intermediate hosts in response to miracidia infection. For this purpose, we performed a histological study of tissue samples of trumpet snails of the genus Planorbis (Müller, 1774) experimentally infected with miracidia Cotylurus sp. isolated from the mallard Anas platyrhynchos (Linnaeus, 1758) of the Perm population and stained by two methods, hematoxylin and eosin, and PAS (periodic acid Schiff reaction). It was found that there were areas of granulation tissue formation in the muscular layer of the leg, which was indicative of the scarring in this organ after mechanical action. Miracidium was also found during migration accompanied by muscle fiber separation and edema development in adjacent tissues. The planorbids’ organism reaction to Cotylurus infection was similar to changes in other related gastropods in response to any infective agent, regardless of its location.